Answer:
6. 7870 kg/m³ (3 s.f.)
7. 33.4 g (3 s.f.)
8. 12600 kg/m³ (3 s.f.)
Explanation:
6. The SI unit for density is kg/m³. Thus convert the mass to Kg and volume to m³ first.
1 kg= 1000g
1m³= 1 ×10⁶ cm³
Mass of iron bar
= 64.2g
= 64.2 ÷1000 kg
= 0.0642 kg
Volume of iron bar
= 8.16 cm³
= 8.16 ÷ 10⁶
Density of iron bar
= 7870 kg/m³ (3 s.f.)
7.
Mass
= 1.16 ×28.8
= 33.408 g
= 33.4 g (3 s.f.)
8. Volume of brick
= 12 cm³
Mass of brick
= 151 g
= 151 ÷ 1000 kg
= 0.151 kg
Density of brick
= mass ÷ volume
(3 s.f.)
Scientists should control most possible variables in experiments to get the most valid and correct data. If many variables are included in experiments it is more difficult to interpret what is causing a different outcome.
Answer:
Mass = 0.37 g
Explanation:
Given data:
Number of moles of sulfur = 11.9 mol
Mass of sulfur in 11.9 mol = ?
Molar mass of sulfur = 32.06 g
Solution:
Number of moles = mass/molar mass
by putting values,
11.9 mol = mass/ 32.06 g/mol
Mass = 11.9 mol × 32.06 g/mol
Mass = 0.37 g
Al is 1.
As for NO3,it is one entity, an the whole thing is being multiplied by 3. Use the distributive property from math.
N is 3.
And O is 9.
In total, there are 13 atoms.
Answer:
Explanation:
Hello,
In this case, the molar enthalpy of reaction is obtained by dividing the involved energy by the reacting moles:
Thus, it is important to notice that the compound "uses" the energy, it means that it absorbs the energy, for that reason the sign is positive. Moreover, computing the result in kJ/mol we finally obtain:
Best regards.
